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United States Patent | 5,060,614 |
Uchimi ,   et al. | October 29, 1991 |
An ignition timing control system for an engine provides a counter-measure for an abnormal condition of a signal. The ignition timing control system has a first signal generator for generating a first signal at intervals of a predetermined crank angle while an engine is rotated n times (n is an arbitrary positive number), this first signal including a marked signal designating a particular cylinder each time the engine is rotated n times; a second signal generator for generating a second signal having pulses in a number equal to that of all cylinders of the engine at intervals of substantially an equal crank angle in synchronism with the first signal, this second signal including a signal of a form which is distinguishable from other second signal and which occurs in synchronism with the marked signal; a unit for producing an ignition signal in response to the first signal; a distributor for receiving the ignition signal and distributing the ignition signal in response to the marked signal of the first signal to each cylinder in a predetermined ignition order; a unit for detecting an abnormal condition of the first signal; and a unit for distributing the ignition signal to each cylinder in a predetermined ignition order in response to the signal synchronized with the marked signal of the second signal in place of the marked signal when the abnormal condition of the first signal is detected.
Inventors: | Uchimi; Kazuhiro (Katsuta, JP); Sasaki; Shoji (Katsuta, JP); Tabuchi; Kenji (Katsuta, JP); Sugiura; Noboru (Mito, JP) |
Assignee: | Hitachi, Ltd. (Tokyo, JP) |
Appl. No.: | 507030 |
Filed: | April 10, 1990 |
Apr 14, 1989[JP] | 1-092870 |
Current U.S. Class: | 123/406.18; 123/612; 123/630; 123/643 |
Intern'l Class: | F02P 007/077 |
Field of Search: | 123/414,612,630,643,479,640 |
4757798 | Jul., 1988 | Sasaki | 123/630. |
4773381 | Sep., 1988 | Koshida | 123/630. |
4941445 | Jul., 1990 | Deutsch | 123/630. |
Foreign Patent Documents | |||
62-651 | Jan., 1987 | JP | 123/414. |
62-38851 | Feb., 1987 | JP | 123/414. |
62-225770 | Oct., 1987 | JP. |